When the fireworks exploded into the Adelaide air after this match, marking Australia Day, it was easy to interpret it as an ironic celebration, for England had won a one-day cricket match at last.

For Jonathan Trott, however, this was merely the maintaining of a continuum, another day on a remarkably successful cricket tour; it also kept up his proud record against Australia, against whom he has now hit four centuries in his still embryonic international career.

When he was included in England's World Cup party earlier this month he probably felt something of a spare part. He was the extra batsman, to come in if injury befell one of the more fashionable players, the powerful and egocentric Kevin Pietersen, the exquisitely gifted Ian Bell or the impish genius that is said to be Eoin Morgan.

But these three have been keenly disappointing, as if in intense competition to be dropped. And now the ugly duckling in the line-up, while never promising to mature into a graceful swan, does have a good chance of making it into the actual team when England open their World Cup campaign with a match against Holland in Nagpur on 22 February.

In the Ashes series his total of 445 runs was bettered only by Alastair Cook. He had an average of 89.00 and scored two centuries. Now he is England's most dependable batsman in this ODI series.

This century followed his unbeaten 84 in the previous match in Sydney. But while there he got bogged down by the constant rattle of wickets at the other end and scored at little more than a run an over at one stage, here he maintained a decent tempo (his strike rate was 80.95, against his 70.59 in Sydney).

There is no longer room for the traditional sheet-anchor role in modern one-day cricket. All batsmen are now required to score at a decent clip. But if Trott can provide reliability and stability there is surely room for him, even if he does not provide the pyrotechnics that illuminated this beautiful ground tonight.

He followed his hundred by taking two wickets in a niggardly seven overs as he and Paul Collingwood took the pace off the ball. Trott said: "I'm very happy to get hundreds and set up a very good total. When called upon to bowl it was very nice to do that as well. So it's happy days.

"Matt Prior made it easier for me, the way he played. But when we lost three wickets it was important that we didn't have a procession of wickets, as in Sydney. It was important that I hung around. I was disappointed to get out at the end, with the power-play looming."

Asked whether he now had the chance to nail down a World Cup place he said: "Definitely, especially with my bits-and-pieces bowling. I've had a word with David Saker [the England bowling coach] and we're going to work hard on that. If I can bowl like Colly [Paul Collingwood] has on this tour it will help the side."

Apart from his runs Trott has the priceless virtue of being able to get under the opposition's skin. Again he managed to get himself between the stumps and the ball when going for tight singles. Again he was hit and at one time it seemed as though he might have obstructed Brett Lee as the fielder attempted to get the ball.

Michael Clarke, the acting Australia captain, who must envy Trott's form, said: "The earlier Jonathan gets in the better it is for him, the more it suits him and allows him to play his natural game. Playing at No3 there is certainly a role for someone like Jonathan. I thought he played well today, held the innings together and allowed the others to bat around him."

England are now 3-1 down with three to play. This was their most impressive performance in the series, though there isn't much in the way of competition.

The captain, Andrew Strauss, said afterwards: "It was a must-win game for us. We came here determined to play well and we're delighted to do well. It gives us some momentum going into Brisbane."

Strauss won the toss yet again and chose to bat on a flat pitch with a fast outfield. And this time there were runs for Prior. Following his ducks in the previous two matches he clumped 67 from 58 deliveries.

England had lost Strauss in the third over – an eventful one, for he was also almost out lbw and caught in the covers. But Prior and Jonathan Trott rollicked along so well that England had 65 on the board after 10 overs, though they faltered once Prior fell, cutting to backward point off Steven Smith.

Pietersen again went for a cameo – this one was even smaller than his usual cameos – and Bell and Morgan failed again. But Trott glued the innings together and a depth-charge from Collingwood and Michael Yardy lifted England to the very brink of 300.

Shane Watson scored his habitual fifty and Cameron White threatened to pull off something special but England relentlessly squeezed the Australians behind the required run-rate. Collingwood, like the man with the red flag who used to walk in front of old-style motor cars, was the most restrictive of their bowlers.